1. Field of the Invention
This invention relates to improved fire retardant siloxane foams and a method for their preparation.
2. Description of the Prior Art
Siloxane foams and methods for their preparation are well known in the prior art, such as for example, as disclosed in U.S. Pat. No. 3,923,705 and U.S. Pat. No. 4,026,842. While these foams have been used in a variety of applications, there has been increasing use of these foams in the construction industry as fire retardant insultation, especially as a protective encasement for mechanical and electrical wires, pipes, conduits, and the like. In an effort to improve the physical properties of the siloxane foams, such as physical strength and fire retardancy, various fillers and additives have been employed. For example, additives such as carbon black, organosilanols, silica, asbestos, potassium titanate, and a variety of other additives have been tried such as disclosed in U.S. Pat. Nos. 4,026,842; 4,026,835; 3,677,981; 3,923,705; 3,425,967; 3,428,580; and 3,338,847. While some of the additives tried heretofore have proven to be satisfactory for specialized applications, none has yielded an economical product for use in the construction industry with sufficient strength, fire retardancy, sealing and wear characteristics and consistency of composition.